Gaucher disease: outcome following total hip replacements and effect of enzyme replacement therapy in a cohort of UK patients

Skeletal Manifestations of Gaucher's Disease: A Case Report and Literature Review

Gaucher's disease (GD) is a lysosomal storage disorder characterized by the storage of glucosylceramide in macrophages ("Gaucher cells"), mainly in the reticuloendothelial system. GD type 1 (GD1) is the most common phenotype that usually manifests with hepatosplenomegaly, cytopenias, and bone involvement. Skeletal manifestations are the most debilitating characteristic and result in significant morbidities. We describe a case of GD1, first presented by a nontraumatic bone fracture. The case presentation highlights the importance of considering GD among the differential diagnosis of nontraumatic fractures, avascular necrosis, and infarcts of the bones. Early diagnosis and treatment improve the course of disease and avoid irreversible sequelae.

Simultaneous Bilateral Femoral Osteonecrosis in Gaucher Disease

Gaucher disease (GD) is one of the most common lysosomal storage disorders. Bone complications are the most critical irreversible consequence of GD. Osteonecrosis (ON) of the femoral head inevitably leads to osteoarthritis and may be managed by hip arthroplasty. The introduction and worldwide use of therapeutic agents (specifically enzyme replacement therapies (ERT)) lowered the prevalence of osteonecrosis events per patient. We present the cases of two female patients who sustained simultaneous bilateral femoral head osteonecrosis after receiving ERT for long periods while exposed to concomitant risk factors related to femoral head ON. Both patients suffered severe pain and deterioration of their daily activity capabilities, and thus, were offered bilateral hip arthroplasty. Surgery was performed in both hip joints during the same procedure. The current report highlights several key aspects of femoral head ON in young patients with GD.

Longevity of total hip arthroplasty implants in patients with Gaucher disease

BACKGROUND

Total hip replacement (THR) is performed for arthritic hip joints, which in Gaucher disease results from osteonecrosis of the femoral head. This procedure was recommended as valid and safe for this group of patients. Nevertheless, long term outcome has not been evaluated in a large cohort.

METHODS

Data regarding all patients having hip replacement in a relatively large Gaucher clinic was collected. Specifically, details such as patient background and quality of life, implant types, radiographic signs of implant-loosening, and success of implant revision were gathered.

RESULTS

The cohort included 48 patients (females 42%, mean age at operation 42 ± 14 years), having 54 hip implants. 15 years survival was 60% and an average implant life was 12.8 years. Longevity was related to implant type, with cementless implants using ceramic-on-ceramic bearing surfaces performing better than other types (no revisions so-far). Older age at surgery also involved a lower revision risk. Gender, disease genotype, and use of cement during the procedure did not have significant effect on longevity. As expected, quality of life and hip related function were better for patients who did not undergo revision. This implies the importance of long-term implant survival.

CONCLUSION

Based on these results we recommend THR as a viable treatment for symptomatic hip arthrosis, especially at older age. Specifically, the utilisation of ceramic on ceramic bearing surfaced shows promising result in patients with Gauchers disease.

Bone disease in patients with Gaucher disease

Gaucher disease is an inborn error of metabolism due to a deficiency of the lysosomal enzyme glucocerebrosidase. As a result of this deficiency, the substrate glucocerebroside accumulates in the liver, spleen, bone and bone marrow. Bone involvement can lead to abnormalities in bone growth, bone remodeling, bone infarcts, aseptic necrosis, osteonecrosis, increased fracture risk and lytic bone lesions. Patients may experience bone pain and bone crises related to bone infarcts. There is evidence of abnormal bone metabolism in both bone resorption and bone formation based upon biochemical abnormalities found in patients. In addition, both immunological and coagulation abnormalities have in part been implicated in the causation of bone disease. Treatment with enzyme replacement therapy and substrate reduction therapy has led to improvement in both the symptoms and the radiographic abnormalities seen in these patients. It is unknown whether these treatments lower fracture risk.

Enzyme replacement therapy (ERT) procedure for mucopolysaccharidosis type II (MPS II) by intraventricular administration (IVA) in murine MPS II

Mucopolysaccharidosis type II (MPS II), or Hunter syndrome, is a lysosomal storage disorder caused by a deficiency of iduronate-2-sulfatase (IDS) and is characterized by the accumulation of glycosaminoglycans (GAGs). MPS II has been treated by hematopoietic stem cell therapy (HSCT)/enzyme replacement therapy (ERT), but its effectiveness in the central nervous system (CNS) is limited because of poor enzyme uptake across the blood-brain barrier (BBB). To increase the efficacy of ERT in the brain, we tested an intraventricular ERT procedure consisting of repeated administrations of IDS (20 μg/mouse/3 weeks) in IDS-knockout, MPS II model mice. The IDS enzyme activity and the accumulation of total GAGs were measured in mouse brains. The IDS activity was significantly increased, and the accumulation of total GAGs was decreased in the MPS II mouse brains treated with multiple administrations of IDS via intraventricular ERT. Additionally, a high level of IDS enzyme activity was appreciated in other MPS II mouse tissues, such as the liver, spleen, testis and others. A Y-maze was used to test learning and memory after repeated intraventricular ERT with IDS. The IDS-treated mouse groups recovered the capacity for short-term memory and activity. Although large and small vacuoles were found at the margin of the cerebellar Purkinje cells in the disease-control mice, these vacuoles disappeared upon treated with IDS. Loss of vacuoles was also observed in other tissues (liver, kidney and testis). These results demonstrate the possible efficacy of an ERT procedure with intraventricular administration of IDS for the treatment of MPS II.